Prior-art large scale photovoltaic power converters essentially use three types of heat removal systems, forced air convection, liquid cooling or a combination of the two. In the forced convection case, fans are required to move ambient air across power converter heat producing or heat-sinking components such as semiconductor devices coupled to heatsinks, magnetic components and power capacitors. In the case of prior-art liquid cooling, fans are used to remove heat from a liquid-to-air heat exchanger. In all cases, the ambient air carries particulate contamination that over time decreases the efficiency of the power converter heat-removal systems. Air filters are not a viable option because of maintenance costs as filters cannot be replaced after every dust storm. Cooling fans are typically the least reliable component in a power conversion system and fan replacement is categorically the highest maintenance cost item over the life of the power converter.
The present invention is a liquid cooled photovoltaic power converter with a liquid-to-earth heat exchanger. With the invention, removal of heat from primary power converter heat sources is accomplished without cooling fans or ambient air exchange in order to eliminate associated particulate contamination and maintenance issues.